1. Field of the Invention
The present invention relates to a rotary trimmer for trimming grass or the like and, more particularly, to a rotary cutting head to be used with the trimmer for cutting the grass with cutting cords or lines extending radially outwardly of a housing which is rotatably driven through a rotating shaft by a motor.
2. Description of the Prior Art
There has been proposed in the prior art a trimmer of the type in which cords (or cutting lines) are found on a supply reel with the free end projecting radially for cutting contact with the plants, e.g., grass or weeds, to be cut upon bodily rotation of the reel. When the exposed length of cords becomes worn, a fresh length is pulled out from the reel by stopping the engine and by disassembling a portion of a trimmer mechanism or loosening retaining screws. As another cord replenishing technique, a push member for moving the reel in the axial direction is attached to the lower end of a cutter head mounting shaft and is depressed axially durings its rotation to move the reel so that the reel and the housing are brought out of phase by the centrifugal force of the cords to play out the required length of cord, as is disclosed in Japanese Patent Laid-Open No. 57-5608.
In the rotary trimmer having the construction according to the prior art, however, it is awkward to play out the cords. When the cords happen to be extended more than necessary during assembly or use, moreover, the excessively long cords cannot be drawn back into the assembly head unless the head is again disassembled, because the reel cannot be accessed from outside the head housing. This makes it necessary to either cut away the excess cord portions and thus waste the same or to disassemble the rotary cutter head. The second prior art technique has the drawback that the depression of the push member during use for feeding the cords radially of the cutter head causes the free ends of the cords to drop down, thereby increasing the danger of scattering stray pebbles or the like and that the presence of the push member raises the height of the cords from the ground and accordingly the effective cutting level of the cords.